A capstan device of a tape machine such as a tape recorder is desirably designed so that the capstan has the axis accurately oriented in a traverse manner relative to the running direction of the tape and also in a parallel manner to the width of the tape, because it significantly effects the running of the tape. If otherwise, the engagement of the tape against the head or heads is unstable, which causes unevenness in the sensitivity, cross talks and poor erasing. Thus, the tape machine with such undesirable capstan device has the poor properties. In addition, worst of all, the tape tends to be damaged. In case where the capstan device is of dual type and if it has the respective capstans unproperly arranged, the capstan device more adversely affect the properties of the tape recorder.
One of the conventional capstan devices comprises a sleeve which includes a flange provided on the periphery of the sleeve and adapted to be secured to the chassis of the tape machine so as to have the axis of the sleeve oriented in a vertical manner and upper and lower bearings fitted into the sleeve at the opposite ends thereof and adapted to extend the capstan shaft therethrough so that the axis of the capstan shaft is oriented in a vertical manner. It is well known that in some cases, the sleeve comprises a double walled sleeve.
However, the sleeve and/or the bearings at the engaging surfaces thereof are difficult to be properly finished due to poor working accuracy and particularly the inside surface of the sleeve which is required to have sufficient length is difficult to be accurately finished by drilling all over length in a normal manner to the plane of the flange. Therefore, they tend to have the axes eccentrically oriented to each other. The fact is also caused by fitting the bearings into the sleeve in an unproper manner so that they misalign with the sleeve. Thus, the capstan shaft cannot be accurately oriented in a vertical manner relative to the plane of the chassis. In order to maintain the alignment of the capstan shaft not only during, but also after assembling the capstan device, the sleeve and/or the bearings must be more accurately finished, which causes the tape machine to be expensive.